[R] can I rotate a matrix

[(Ted Harding)]

On 18-Mar-10 19:10:46, dc896148 wrote:
> useR's,
> I want to be able to rotate a matrix 90 degrees, clockwise.
> For > example, 
>> mat
>      [,1] [,2] [,3]
> [,1]   1    2     1
> [,2]   3    2     6
> [,3]   4    5     3
> 
> I want to rotate it, so that it looks like this...
>      [,1] [,2] [,3]
> [,1]   4    3     1
> [,2]   5    2     2
> [,3]   3    6     1
> 
> Does anyone know a quick and straightforward way to do this?
> 
> Thanks in advance.
> -- 

  mat
  #      [,1] [,2] [,3]
  # [1,]    1    2    1
  # [2,]    3    2    6
  # [3,]    4    5    3

  matrix(rev(mat),nrow=3,byrow=TRUE)[(3:1),]
  #      [,1] [,2] [,3]
  # [1,]    4    3    1
  # [2,]    5    2    2
  # [3,]    3    6    1

How's that? (But straightforward? Straightbackward, more like).
Ted.

--------------------------------------------------------------------
E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 18-Mar-10                                       Time: 19:57:07
------------------------------ XFMail ------------------------------